D. A family triumphs over a difficult passage across the sea
Explanation:
It is no secret that the passage is difficult. It's also a fact that they were able to triumph over this passage. No where in this sentence does it state an opinion. "Better" or "bad" is used as opinions about the different places.
To say that the passage is the most difficult could count as an opinion it may not be the most difficult. This makes a judgement that this is the most difficult.
